JEE Main Chemistry question
The ionisation constant of NH₄⁺ in water is 5.6×10⁻¹⁰ at 25°C. The rate constant for the reaction of NH₄⁺ and OH⁻ to form NH₃ and H₂O at 25°C is 3.4×10¹⁰ L mol⁻¹s⁻¹. The rate constant for proton transfer from water to NH₃ is:
Answer: (A)
Solution
Kb(NH₃)=Kw/Ka=1.79×10⁻⁵=k(forward)/k(given,reverse); k(forward)=1.79×10⁻⁵×3.4×10¹⁰≈6.07×10⁵ s⁻¹.